blocks|key|2515842|text|好吧，那么问题是你为什么要这个。这是为了使这种比较变得容易：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2515843|$count+=+10;++++
while($count){
++++echo+$count;
++++$count--;
}|code-block|syntax|javascript|2515844|这可以让你决定数字模型的计数，是否有任何东西。|2515845|在null中也会发生同样的情况，您可以很容易地检查变量是否有指定的值。|offset|length|style|CODE|2515846|对于数组，它允许您检查数组是否为空。|2515847|entityMap^0|0|0|0|1|4|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|V|8|@$K|W|L|X|M|N]]|9|@]|A|$]]|$1|O|3|P|5|6|7|Y|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

Ok, so the question is WHY would you want this. This is to make this kind of comparisons easy:

<pre><code>$count = 10; 
while($count){
 echo $count;
 $count--;
}
</code></pre>

This allows you to decide whether numbers that model a count, have anything or not. 

The same thing happens with <code>null</code>, you can easily check if a variable has a value assigned or not.

In the case of arrays, it allows you to check wether the array is empty.

blocks|key|345027|text|这里是原因所在。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|345028|案例一将将array()转换为布尔值，从而生成false。|style|CODE|345029|在这里解释了案例2和案例3，标量被转换为数组：|345030|对于任何类型:整数、浮点数、字符串、布尔值和资源，将值转换为数组将产生一个具有索引为零的单一元素的数组和转换的标量值。换句话说，(数组)$scalarValue与数组($scalarValue)完全相同。|blockquote|345031|下文对案例四作了解释：|345032|将NULL转换为数组将导致空数组。|345033|entityMap|0|LINK|mutability|MUTABLE|url|http://www.php.net/manual/en/language.types.array.php#language.types.array.casting^0|0|2|0|0|5|7|N|5|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@$A|Z|B|10|1|11]]|C|$]]|$1|D|3|E|5|6|7|12|8|@$A|13|B|14|F|G]|$A|15|B|16|F|G]]|9|@]|C|$]]|$1|H|3|I|5|6|7|17|8|@]|9|@]|C|$]]|$1|J|3|K|5|L|7|18|8|@]|9|@]|C|$]]|$1|M|3|N|5|6|7|19|8|@]|9|@]|C|$]]|$1|O|3|P|5|L|7|1A|8|@]|9|@]|C|$]]|$1|Q|3|-4|5|6|7|1B|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]]]

<a href="http://www.php.net/manual/en/language.types.array.php#language.types.array.casting" rel="nofollow">Here</a> is the reason why.

Case one will cast the <code>array()</code> to a boolean, resulting in <code>false</code>.

Case two and three are explained here, the scalars are cast to arrays:

<blockquote>
 For any of the types: integer, float, string, boolean and resource, converting a value to an array results in an array with a single element with index zero and the value of the scalar which was converted. In other words, (array)$scalarValue is exactly the same as array($scalarValue). 
</blockquote>

Case four is explained here:

<blockquote>
 Converting NULL to an array results in an empty array. 
</blockquote>

blocks|key|2515896|text|这都是关于类型杂耍，哪种类型赢了另一种类型。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2515897|例如，当您将一个数字与一个字符串进行比较时，该数字总是获胜，因此该字符串将被转换为一个数字。因此，"12abc"+==+12在PHP中是正确的。|offset|length|style|CODE|2515898|当将布尔值(false)与某物进行比较时，将某物转换为布尔值。(bool)+array()是false，所以false+==+false是真的。|ordered-list-item|2515899|当将另一个值与数组进行比较时，其他值被转换为array([0]+=>+VALUE_OF_OTHER)+(换句话说，转换为数组)。这意味着比较变成了array('')+==+array()，这是错误的。|2515900|与(2)相同。array(0)+==+array()是假的|2515901|array(null)意味着一个没有任何东西的数组，因此array(null)+==+array()+(这是您所做的比较)，所以结果是正确的。|2515902|entityMap^0|0|1D|D|0|6|5|V|E|1A|5|1I|E|0|M|S|21|K|0|7|J|0|0|B|S|M|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@$D|U|E|V|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|W|8|@$D|X|E|Y|F|G]|$D|Z|E|10|F|G]|$D|11|E|12|F|G]|$D|13|E|14|F|G]]|9|@]|A|$]]|$1|K|3|L|5|J|7|15|8|@$D|16|E|17|F|G]|$D|18|E|19|F|G]]|9|@]|A|$]]|$1|M|3|N|5|J|7|1A|8|@$D|1B|E|1C|F|G]]|9|@]|A|$]]|$1|O|3|P|5|J|7|1D|8|@$D|1E|E|1F|F|G]|$D|1G|E|1H|F|G]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|1I|8|@]|9|@]|A|$]]]|R|$]]

It's all about type juggling, which type wins over the other type.

For instance, when you compare an number with a string, the number always wins so the string will be converted into a number. So <code>"12abc" == 12</code> is true in PHP.

<ol>
<li>When comparing a boolean (<code>false</code>) with something, that something is converted to a boolean. <code>(bool) array()</code> is <code>false</code>, so <code>false == false</code> is true.</li>
<li>When comparing another value with an array, the other value is converted to <code>array([0] =&gt; VALUE_OF_OTHER)</code> (in other words, converted to an array). That means that the comparisation becomes <code>array('') == array()</code>, which is false</li>
<li>Same as (2). <code>array(0) == array()</code> is false</li>
<li><code>array(null)</code> means just an array with nothing, thus <code>array(null) == array()</code> (which is the comparisation you did), so the result is true.</li>
</ol>

I'm a curious programmer. So these days I was reading the documentation from the PHP site and this link was "PHP type comparisons" <a href="http://www.php.net/manual/en/types.comparisons.php" rel="nofollow">http://www.php.net/manual/en/types.comparisons.php</a>

I decided to do some exercises to fill the tables of comparisons but there are some answers that I can not see why, for example:

<pre><code>&lt;?php
var_dump(false == array()); // Okay, an empty array is considered false. True result
var_dump('' == array()); // false ? Why not true if an empty string is considered false ?
var_dump(0 == array()); // false ? Why ?
var_dump(null == array()); // true. Why ?
?&gt;
</code></pre>

Can you help me about this? I can not understand why some comparisons, I can not find anywhere explanation.

PHP loose comparison with ==

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我是个好奇的程序员。因此，这些天我从PHP站点阅读文档，这个链接是"PHP类型比较“。我决定做一些练习来填写比较表，但有些答案我看不出来，例如：<?phpvar_dump(false == array()); // Okay, an empty array is considered false. True resul...

问与==的松散比较
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